Note: Descriptions are shown in the official language in which they were submitted.
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FOLDING APPARATUS AND METHOD
BACKGROUND AND SUMMARY OF INVENTION:
This invention relates to a folding apparatus and
method and, more particularly, to an improved tucker for a
grippex-tucker type folder.
Rotary folders have been known for a long time -- see
for example, co-owned U.S.~Patent No. 3,195,882. Such
folders employed tuckers and grippers for achieving web
; folding and for the most part, the tuckers were fixed within
the foldlng roll or rotating member. In some instances, the
tuckers were spring loaded as exemplified by U.S. Patent No.
;4,270,744.
I have found that substantially improved performance
can be achieved by changing the mounting of the tucker to a
free floating style with limited movement. This and other
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attrlbutes of the invention are set forth in the ensuing
specification.
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The invention in one aspect provides an apparatus for
folding webs having a pair of rolls each e~uipped with
tuckers and grippers and arranged for a tucker of one roll
to enter into a gripper of the other roll, the improved
tucker construction comprising an elongated member having a
gripper-entering tip at one end and a pivot mounting at the
other end. Pivot means is on each roll for mounting the
elongated member in unbiased, free floating condition, and
abutment means is on each roll radially outward of the pivot
means for limiting the amount of member~free float to a
predetermined value and for immobilizing the member for
initial tlming of the rolls.
The invention also provides a method of operating a
folder having a pair of rolls each equipped with tuckers and
lS gr~ippers and arranged for a tucker of one roll to enter into
the gripper of the other roll, the tucker being an elongated
member having a gripper-entering tip at one end and a pivot
mounting at the other end, and each roll having abutment
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~ ~ means located radially outward of the pivot means for
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~20 limiting the amount of pivotal movement of the elongated
~;~ member.~ The method comprises mounting the tuckers for
unbiassd, slight free floating movement at the gripper
entering end.
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The invention is described in conjunction with an
illustrative embodiment in the accompanying drawing in which --
FIG. 1 is a fragmentary end elevational view ofapparatus embodying the teachings of this invention and
featuring a pair of coacting folding rolls, each equipped with
tuckers and grippers;
FIG. 2 is an enlarged fragmentary view showing the
tucker of one roll about to enter the gripper of the companion
roll; and
FIG. 3 is a perspective view, partially exploded, of
one o~ the identical folding rolls.
DETAILED DESCRIPTION: ~
In the illustration given and with reference to FIG. l,
the numeral 10 designates generally a folding roll such as would
be positioned on the front of folding apparatus while the
numeral 11 designates generally an identical folding roll
~positioned on the xear of the apparatus. Each of the rolls 10
and 1l are "four tlme" rolls, i.e., each having four tucXers 12
and four grippers 13. As can be readily appreciated, the
20 ~orlentation of the rolls is such that the tucker of one roll
enga~es the gripper of the other roll. In the illustration
given, this is illustrated by the rolls being phased or
angularly offset 45 relative to each other.
Each roll 10 and ll is seen to have tuckers 12
arranged at 90 relative to each othe as are the
intermediate grippers 13. The roll seen in FIG. 3 is equipped
~with shaft extensions, one of which is seen at 14 at
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the right hand end for rotatably mounting the rolls in a
conventional frame (not shown).
As can be hetter appreciated from a consideration of
FIG. 2, each gripper assembly 13 includes an anvil 15 and a
gripper element 16 mounted on a pivot shaft 17. The shaft 17 is
actuated by a cam mechanism generally designated 18 in the
central part o~ FIG. 1. This much is conventional and may be
varied depending upon the specifications of the particular
folder~
In the left hand portion of FIG. 2, it will be seen
that the tucker 12 includes an elongated member 19 equipped with
a pointed end 20 for insertion between the jaws:o~ the gripper
13' ~ormed by the:anvil 15 and the gripper element 16.
In the illustration given and with reference to FIG. 3,
lt will be seen that a pair of:elongated members 19 are provided
in end-to-end relation. Each member 19 at its radially inward
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; ;side is equipped with an axially-extending stub shaft 21.
Ensleeved on each shaft 21 is a:bushing 22 which is received
w1thin a bearing block 23 removably fixed to cast, machined body
10':. In this fashion, the tucker elements 19 are free to pivot
or "float".
~;~ To insure floatability of the tucker elements 19, .he
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body 10' is machined with a gap 24. This advantageously isof the
order of about 1/16" allowing the tucker to "float" during
25 . operation, viz., when it engages a web for moving the same into
the space between the gripper jaws.
: The tucker gap is advantageously provided tbrough
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recessing the body 10' as at 25 for a portion of its radial
extent but leaving an abutment part 26.
I have found that it is important to limit the total
free movement of the tucker to prevent rolls from destroying
themselves during operation. With the free floating tucker of
the invention, it is possible to obtain a 50% increase in the
speed of the web being folded between the rolls 10 and 11 and it
also allows the running of material of different thicknesses
without the need for adjusting or resetting the folding rolls.
Lastly, and by no means less important, is the fact that the
folder runs much quieter.
In operation, the tucker 12 through its elongated
member 19 which is free floating, tucks the material between the
jaws of the gripper anvil 15 and the movable gripper blade 16.
Advantageously, the included angle on the tucker is of the order
of 60 as 1llustrated.
As indicated previously, the movement of the gripper
blade 16 is controlled by the cam mechanism 18 and gripper
receives the web material which has been partially creased by
~20 enga~ement with the tucker. The gripper traps the material and
carrie~ the same a given distance before releasin~g so as to
achieve zig-zag or interfolded web material~ Thus, it is
advantageous for use in facial tissue, single fold tissue,
multi-fold tissue and the like.
The cam mechanism 18 as seen in FIG. 1 includes a clamp
block 27 fixed to the pivot shaft 17. The clamp block 27 in
turn carries a cam follower roller 28. More particularly, the
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cam followers 28 are each rotatably mounted on stub shafts 29
carried by the plurality of clamp blocks 27~ Entrained about
the four (as shown) cam follower stub shafts 29 is a urethane
belting 30 urging the followers 28 against the periphery of a
stationary cam 31. The cam 31 is advantageously provided as
part of the frame of the machine.
The cams 31 are equipped with depressed portions as at
32 permitting radially inward movement of the follower
associated with the gripper being closed -- as at 13' in FIG.
10 1.
The distance the tucker is allowed to float is
dependent upon each particular layout but excellent results have
been found in the normal folder with an allowable movement of
approximately lJ16".
15The locating abutment or shoulder 26 is advantageous in
that during initial installation and setup of the rolls, the
floating tucker has to be held against this shoulder by set
screws 33 to properly time the rolls. After timing is complete,
the tucker is released by backing out the set screws 33 and
allowed to float free. The recess 25 behind the abutment 26
: ~ also provides a space for the accumulation of any debris or dirt
that would build up in the folding rolls.
: While in the foregoing specification a detailed
description of an embodiment of the invention has been set down
for the purpose of illustration, many variations in the details
: hereingiven may be made by those skilled in the art without
departing from the spirit and scope of the invention.
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